Family stress has been linked to asthma onset, symptom severity, and exacerbation. Biopsychosocial models propose that the relationship between family stress and asthma expression may be mediated by physiological systems, including the hypothalamic-pituitary-adrenal (HPA) axis. The typical pattern of HPA axis reactivity in children with asthma is unclear, however. Whereas some investigators have found elevated cortisol levels, others have found blunted levels. This lack of clarity in HPA axis activity is a rate-limiting factor for the development of biopsychosocial models of asthma and may present an obstacle for understanding the mechanisms of treatment. With the proposed study and training plan, I seek to develop skills in measuring and interpreting cortisol variation as it relates to family psychosocial stress in children with asthma. I also want to further my understanding of psychosocial family stress to provide a basis for developing family-based interventions and stress-reduction programs for children with asthma, a future career goal. Family conflict and insecurity of attachment, which have often been included in theoretical models of child health, are two key constructs identified in models of asthma and in research assessing HPA axis function and child well-being. Yet, no study has examined these stressors in children with asthma in relation to their experiences of specific family psychosocial stress. The aims of this study will be to examine the links between insecure attachment and family conflict and individual differences in asthma severity, indexed by clinical evaluation and medical complications;we will also investigate the exploratory hypothesis that the association between psychosocial family stresses and asthma outcomes is mediated by HPA axis functioning. Assessments will include observations, interviews, questionnaires, and medical data;in addition, for HPA axis function, both diurnal and reactivity measures will be included. The sample will be composed of 6-8 year-old children, with a high percentage of low-income and minority families;they will be selected form a larger ongoing study of asthma at the University of Rochester Medical Center. The public heath relevance of the study is substantial because asthma is the most prevalent pediatric chronic illness, and the rates are rising, especially among low-income children. Clarifying the relationship between psychosocial family stress and the HPA axis may provide empirical support for further development of biopsychosocial models and inform intervention programs for children and families.